Push tug-barge thrust transmittal means

ABSTRACT

Thrust transmittal means for push tug and barge comprises, on the barge, a rearwardly projecting thrust receiving member having a hemispheric convex rear surface and, on the tub, a concave hemispheric thrust exerting surface. Preferably, a plurality of such thrust exerting members are disposed at vertically spaced points along the bow of the tug. An articulated joint to permit relative pitching of tug and barge is thus provided with no coupling device other than the normal chains, cables or lines, suspended in tension between the tug and barge to prevent separation thereof. Preferably, such chains, cables or lines include a hook and eye link with releasable retainer to facilitate unhooking of same, even under emergency conditions. At the rear of the barge, a deep notch with sidewalls is provided to receive the bow of the tug with fenders between these sidewalls and the adjacent tug sides to prevent relative roll between tug and barge.

This application is a continuation-in-part of our earlier filedapplication, Ser. No. 602,557, that was allowed July 29, 1976 and is nowU.S. Pat. No. 3,993,014.

This invention pertains to a push tug-barge thrust transmittal means andmore particularly to a simplified articulated thrust transmittal meanswhich permits moving tow in moderately high seas. Still moreparticularly, this invention relates to such a thrust transmittal meanswhich does not include a mechanical coupling, and which thereforefacilitates expedient disengagement of tug and barge, when necessary.

Push tug-barge combinations are generally unable to tolerate high seas.To rectify this problem, various means have been proposed, some of whichpermit some relative movement between tug and barge. A type of suchthrust transmittal means is generally referred to as articulatedcouplings. Such couplings are seen, for example, in U.S. Pat. Nos.1,550,354--Foulkes, 2,715,380--Archer, 3,035,536--Archer,3,109,406--Stockdale, 3,461,829--Mosvold, 3,568,621--Kawasaki,3,654,225--Lunde, 3,802,375--Janssen, 3,804,052--Lucht,3,830,136--Janssen, 3,605,675--Clemence, Jr., 3,756,183--Clemence, Jr.,and 3,735,722--Hooper, the last three being of common assignmentherewith.

All of the designs heretofore known have, however, included certaininherent shortcomings. Among those designs shown in the above citedprior art patents, several include mechanical coupling retainer means aspart of the thrust transmittal system, such as the thrust transmittingmembers including securing means to prevent coupling disengagement. Suchmeans interfere with the rapid disengagement of the tug and barge,should such disengagement become necessary under emergency conditions.Perhaps for this reason, the Coast Guard has indicated that a tug-bargecombination with such coupling means must be considered an integratedunit, with attendant inspection, certification and crew requirementsbeyond that necessary for tug and barge ordinarily.

In addition, at least one thrust transmitting means has been proposed,which appears to permit articulation but which actually does not. Uponclose inspection of U.S. Pat. No. 2,684,653--Dyer, it is noted that flatabutting surfaces 38, 39 are provided with an elongated thrust memberextending into an elongated receptacle (see particularly FIG. 2 of thatpatent) which prevents such articulation as may necessary to permit theengaged tug and barge to remain in engagement in heavy seas.

Further, a commercially operating push tug-barge arrangement is known inwhich thrust transmittal is accomplished through members projectingforwardly from the tug and rearwardly from the barge, the mating ends ofthe projecting members including a cylindric convex surface member atthe end of the rearwardly projecting barge piece and a cylindric concavesurface at the forward end of the bow piece. This arrangement permitsarticulation between barge and tug in a vertical plane about the pointof engagement of the thrust transmitting device. A notch with rearwardlyextending sidewalls on the barge and fenders between the tug and bargeprevent relative roll in this system.

Having in mind all of these problems, it is the general object of thepresent invention to provide a push tub-barge thrust transmittal meanswhich facilitates both engagement and disengagement of the tug andbarge, which is relatively simple, though effective, and which permitssome interchangeable use of tug and barge with other barges and tugs notincluding the thrust transmittal means of this invention.

A further object of this invention is to provide an articulated thrusttransmittal means for a push tug and barge which permits the tug andbarge to remain in engagement in relatively high seas but which alsopermits rapid disengagement under emergency conditions.

A more specific object of this invention is to provide such a thrusttransmittal means which may be adapted to permit engagement of tug andbarge at different relative drafts of tug and barge and in which fixedlateral positioning of tug and barge is assured.

These objects, and others which will be apparent in the course of thesubsequent description, are met, briefly, by a push tug and barge thrusttransmittal means comprising a cylindrical member projecting rearwardlyfrom the stern of the barge, that member including a convex hemisphericsurface at its rearward end, and a thrust exerting member on the bow ofthe tug on the center line thereof, the thrust exerting member having aconcave surface adapted to mate with the convex rearward surface of thestern member. Preferably, the convex and concave surfaces arehemispheric, so that the mating surfaces are self-centering. Theseconcave-convex mating surfaces of the thrust transmittal means of thisinvention permit relative pitching, or articulation, between and tug andbarge. This permits tug and barge to remain in engagement despiterelatively high seas. The mating surfaces may be lubricated to reducefrictional restraint of this motion. The degree to which suchlubrication may be required is not known. However, lubrication groovesshould be provided to run longitudinally on the thrust receiving memberextending from the barge, the longitudinal grooves termination at thecenter point of the convex hemispheric thrust receiving surface.Further, an automatic lubrication system may be provided, with itssingle outlet at the central point, communicating with a passagewaywithin the projecting member and a lubricant source with means forpressurizing same to drive lubricant to the central point of the frontof the thrust receiving member and then into the lubricant grooves. Thislubrication system can be used to lubricate the mating thrust exertingand thrust receiving surfaces even while the tug and barge are inengagement.

A deep notch with extended sidewalls at the rear of the barge isprovided to receive the bow of the tug. Fenders or bumpers between thesesidewalls and the sides of the tug limit relative rolling motion betweentug and barge and assure correct lateral positioning of tug and barge.Since these contacting fenders or bumpers experience some relativevertical motion of tug and barge during relative pitching of tug andbarge, the frictional restraint on this movement may be reduced bylubricating these surfaces or by providing rollers or other similarmechanical means on either the tug or barge to mate with the otherwisestandard adjacent fenders. To provide greater contact area, the bargenotch sidewalls may be provided with bulwarks, above the deck level ofthe barge, and deep keels, by plating extending upwardly and downwardlyfrom along the notch sidewalls.

The cylindrical projecting member on the stern of the barge may also beretractable, by any conventional retraction means, so as to facilitatethe use of the barge with tugs that are not equipped with the concavethrust exerting members as disclosed in this invention.

In any event, upon pushing engagement of the thrust transmittal means ofthis invention and the tug and barge including such thrust transmittalmeans, separate means may be provided to restrain by conventional means,such as cables, chains or hawsers suspended in tension between the tugand barge, the tug and barge from separating from one another. Theprimary thrust transmittal means described above, together with theserestraining means, are all horizontally disposed from one another sothat when tug and barge are in engagement all of their connections liein a common horizontal line, which serves as a hinge line similar to thehinge concept of earlier articulated push tug-barge couplings, such asthose shown in the previous patents of the assignee of this invention,referred to above. In accordance with present practice, the hawsers,chains or cables holding tug and barge together may be quickly releasedin order to facilitate rapid disengagement of tug and barge underemergency conditions. Preferably, such chains are hooked to postsprovided on the stern of the barge on either side of the thrusttransmittal means and coplanar therewith. On the tug, the chains arehooked to releasable links which permit the tensioned chains to bequickly removed from their hook points on the tug. This is particularlyimportant to facilitate separation under emergency conditions. Thepreferred means comprises a hook in engagement with the chain. Whenseparation is desired, the retainer is removed from the hook and thehook pivots away from its engaged position and the chain is released.

Finally, in order to accomodate the thrust transmittal means of thepresent invention to the differing relative drafts of the tug and bargedepending upon the load of each, a plurality of thrust exerting membersmay be provided on the bow of the tug, these members of course beingvertically spaced from one another to receive the thrust receivingmember (projecting from the barge) at a convenient vertical position,depending on the drafts of tug and barge at the particular time ofengagement.

This invention may be better understood by reference to the followingdetailed description of the preferred embodiment thereof, taken inconjunction with the sub-joined claims and the drawings, in which:

FIG. 1 is a plan view of a push tug and barge, showing one embodiment ofthe thrust transmittal means of the present invention wherein theprojecting member is located on the bow of the tug, with the matingconcave hemispheric surface located on the stern of the barge; the tugand barge are shown in their engaged positions;

FIG. 2 is a schematic sectional elevation view of the engaged tug andbarge shown in FIG. 1;

FIG. 3 is a sectional plan view of the embodiment of the thrusttransmittal means as shown in FIG. 1;

FIG. 4 is a sectional view, in the plane 4--4 of FIG. 3 of the chainreleasing means shown in the assembly of FIG. 3;

FIG. 5 is a plan view of a push tug and barge showing another embodimentof the thrust transmittal means of the present invention wherein theprojecting member is located on the stern of the barge, with the matingconcave surface located on the bow of the tug; the tug and barge areshown in their engaged positions; and

FIG. 6 is a schematic sectional elevation view of the engaged tug andbarge shown in FIG. 5.

FIGS. 1 through 4 describe subject matter disclosed and claimed in ourearlier filed parent application, Ser. No. 602,557. A detaileddiscussion of these Figures is essential to an easy understanding of theembodiment of the thrust transmittal means disclosed in thiscontinuation in part application.

Referring more specifically to FIG. 1, there is seen push tug 10 andbarge 12. Mounted on the tug 10 is a thrust transmitting cylindricalforwardly projecting beam member 14 with a hemispherically convexfrontal surface 16. Frontal surface 16 is received in centrally mountedthrust transmittal receiving member 18 on the stern of barge 12. Chainmeans 20 are provided to prevent separation of tug 10 from barge 12while they are in their engaged positions. Barge 12, at its rear,includes a deep notch 24 for receiving the bow 26 of the tug 10;sidewalls are extended upward with bulwarks 22a and downward with deepkeel-like extenders 22b. The bow 26 of the 10 with fenders 28 fits innotch 24, with fenders 28 preventing actual contact of tug 10 and barge12. Bulwarks 22a and extenders 22b provide greater contact area forfenders 28 and ensure contact despite relative pitching of tug andbarge. Fenders 28a, which do not contact barge 12, are also providedforward on tug 10 for use of tug 10 in combination with other tugbarges.

As better seen in FIG. 2, beam member 14 with hemispheric convex frontalsurface 16 is received in thrust receiving member 18 in a hemisphericconcave surface 30 to facilitate articulation therebetween, particularlyin a vertical plane, as seen by the phantom position lines of barge 10shown in FIG. 2. In the enlarged sectional view of the thrusttransmittal means of this invention used in tug 10 and barge 12, takenin the plane 3--3 of FIG. 2, and which is shown in FIG. 3, forwardlyprojecting beam 14 is seen at its rear end to include a threaded member32 in internally threaded retainer 34. In this preferred form of thepresent invention, beam 14 may be retracted by threaded member 32 inretainer 34 in order to permit the use of tug 10 as a push tug withother non-mating barges.

Hemispherically concave surface 30 is flared outwardly toward the rearof barge 12 to facilitate proper receiving and positioning of beammember 14 in receiving member 18. It will be noted that the receivingmembers for the thrust transmittal means of this invention on barge 12do not project rearwardly therefrom. Barge 12 is therefore adapted to beused with other non-mating tugs. For accomodating different relativedrafts of tug and barge, additional thrust receiving members 18A and 18Bare disposed at vertically spaced positions from member 18.

Referring again to FIG. 3, and to the sectional view of the chainlocking means of FIG. 4, it should be noted that while the thrusttransmittal means of the present invention permits ready positioning andengagement with no locking or coupling mechanism, means are generallyprovided to prevent separation of tug and barge. Preferably, such meansinclude tensioned hawsers, chains or cables, such as chains 36 withshackles 38 engaging posts 40. provided for that purpose of the stern ofbarge 12. Chains 36 are pivotally connected to a fastening member 42 ontug 10, with a length adjustment means, such as turnbuckles 44. Further,chains 36 preferably associated with a quick disconnect means, such ashook 46. Hook 46 is pivoted at pivot connection 50 and the configurationof hook 46 is such that with chains 36 in tension, hooks 46 tend toslide out of and become disengaged from chains 36. To prevent any suchaccidental disengagement, a releasable retainer 54 is provided. Retainer54 is simply pulled upwardly (as seen in FIG. 4) to release chains 36and permit separation of tug and barge. Chains 36 slide forward insleeves 56 and out of tug and the untensioned chains 36 are then left tohang free on posts 40.

While other quick disconnect means may be used for the tensioned chainspreventing separation of tug and barge, such connecting anddisconnecting means for chains are similar to those used conventionally.

Referring now to FIGS. 5 and 6, there is shown an embodiment similar tothat shown in FIGS. 1 through 4 except that projecting thrust member 60is mounted on the deck of the stern of barge 12 and on the bow-sterncenter line. Rearwardly projecting member 60 includes a hemispheric,convex surface at its rearward terminal point. Thrust receiving member60 is securely anchored by mounting blocks 62, 64 that are firmlyattached to the barge deck. Member 60 includes threaded member 32 thatextends from the rear end of beam 14 (similar to that shown in FIGS. 1through 4). Mounting block 62 includes a cylindrical aperture 68 drilledtherethrough to allow for the forward withdrawal of beam member 14 bythreaded member 32 in retainer 34 in order to permit the use of barge 12with other non-mating tug boats.

Hemispheric, concave thrust exerting surface 66 is located on the outerforwardmost portions of the bow of tug 10. Thrust exerting surface 66 iscentered on the tug's stern-to-bow center line and is adapted to matewith thrust receiving member 60 projecting from the barge's stern. Ifdesired, a plurality of concave thrust exerting surfaces 66A, 66B may bevertically spaced from one another along this same center line. In suchmanner, different relative drafts of tug and barge may be easilyaccomodated.

Means similar to that exhibited in FIGS. 3 and 4 are provided to preventseparation of tug and barge.

Also, deep notch 24 receives the bow 26 of tug 10 in the exact mannerillustrated in the description of FIGS. 1 through 4. Bulwarks 22a,extenders 22b and bow fenders 28 provide a cusioned contact area betweentug and barge and ensure vessel contact despite relative pitching of tugand barge.

Accordingly, it will be apparent that the thrust transmittal means ofthe present invention, whether the projecting member is mounted on thebow of the tug or on the stern of the barge, not only provides a simplearticulated engagement between tug and barge, but it does so in a mannerrequiring no lock up or coupling in the thrust transmittal means otherthan chains, cables or hawsers.

The present invention has been demonstrated to be both effective andefficient. As compared to conventional tug-barge systems, hydrodynamicdrag is considerably reduced, course stability is improved, and a quickreleasable push tug-barge thrust transmittal system, capable oftolerating moderately high seas, is thus obtained. In general, increasedspeeds are obtainable, and the overall net effect is an improvement infuel efficiency over conventional tug-barge systems.

While this invention has been described with reference to a specific andpreferred embodiment thereof, it should be understood that it is notlimited thereto and numerous equivalent variations and modifications maybe made by those skilled in the art without departing from the truespirit and scope thereof.

It is apparent that the embodiment disclosed in FIGS. 1 through 4 issimilar to that embodiment disclosed in FIGS. 5 and 6. However, in theembodiment illustrated in FIGS. 5 and 6, the convex mating surface isdisposed on a member associated with the barge, rather than the pushtug. A mating concave pushing surface is associated with the tug. Theretractable beam is associated with the barge rather than the tug andthe thrust transmittal member of the tug is a bow mounted,non-projecting member with a concave pushing surface.

A further feature of the preferred embodiment of this inventiondescribed and illustrated in FIGS. 5 and 6 above is a yoke and pin meanslocated at the forward end of thrust member 60. With member 60 in itsrearward, projecting position, the yoke and pin means is secured to ahull member, such as a mounting block, so that the full thrust force isnot exerted through the threads of threaded member 32 but rather throughthe yoke and pin means.

Still another extension of this invention involves modification of thefront of the barge of this invention to provide a bow with a concavepush surface similar to that shown on the bow of the tug as seen inFIGS. 5 and 6, to permit mating of several such barges and therefore topermit multiple barge pushing. All such modifications and variations areintended to be covered by the appended claims.

Having thus described our invention, we seek to secure by Letters Patentthe following:

We claim:
 1. Push tug and barge with thrust transmittal meanscomprising:a. a thrust receiving member projecting rearwardly from thestern of said barge along its center line, said rearwardly projectingmember including at its rear terminal point a convex hemisphericsurface; b. a non-projecting thrust exerting member mounted on the bowof said tug, said thrust exerting member having a hemispheric concavesurface adapted to receive and mate with the convex surface of saidthrust receiving member; c. said two mating surfaces formed between saidthrust receiving and thrust exerting members providing the sole means oftransmitting pushing thrust to said barge from said tug while permittingrelative pitching therebetween; d. a notch at the stern of said bargewith sidewalls on the two sides thereof, said barge stern and sidewallsand the bow of said tug being adapted so that said bow fits between saidsidewalls upon engagement of said tug and barge, including fenders,rollers or other means through which contact is made between saidsidewalls and said side of said tug to limit relative motiontherebetween; and e. quickly releasable means independent of saidcylindric and thrust receiving members, to restrain said tug and bargefrom separating from one another.
 2. Push tug and barge, as recited inclaim 1, wherein said tug includes a plurality of hemispheric concavethrust exerting members, said thrust exerting members vertically spacedfrom one another along the bow-stern center line.